I use a similar method as Mochi, but I use Javascript to autofill the Subject field with a Unix Timestamp giving me a unique number at the end of each subject, then I set the CSS value of the form Subject field and it's Label to none, making it invisible to the user. The Subject field has to be the first field of the form for this to work, as it has no defining attributes, so this simply modifies the 1st field. Seems to be working so far.
PAGE HEADER CODE INJECTION
<script>
$(document).ready(function(){
var timecode = Date.now();
var subjecttxt = "#" + timecode;
$('form').find("input[type=text], text").each(function()
{
if(!$(this).val()) {
$(this).attr("value", subjecttxt);
$(this).attr("readonly", true);
$(this).css("display","none");
var val = subjecttxt;
return ( val !== subjecttxt );
}
});
});
$(document).ready(function(){
$('form').find("label[class=title]").each(function()
{
if(!$(this).val()) {
$(this).css("display","none");
var val2 = "none";
return ( val2 !== "none" );
}
});
});
</script>